Lancom Systems LCOS 3.50 Uživatelský manuál Strana 222
- Strana / 346
- Tabulka s obsahem
- KNIHY
Hodnocené. / 5. Na základě hodnocení zákazníků
LANCOM Reference Manual LCOS 3.50 Chapter 11: Wireless LAN – WLAN
222
Wireless LAN – WLAN
The access point is thus a sort of middle man between client and server. it
doesn't have to check the contents of these packets, it just has to check that
no other data traffic to or from the client can occur.
This process has two advantages:
The implementation effort in the access point is low. While the client and
the server are usually PCs with high levels of resources, access points are
devices which are limited both in memory and in computing power.
New processes for authentication require no firmware upgrade on the
access point.
Over this tunnel through the access point, the client and server authenticate
one another, that is, the server checks the client's access privilege to the
network, and the client checks that it is talking to the right network. "Wild"
access points set up by hackers can be recognised in this way.
A whole series of authentication processes exist which can be used in this
tunnel. A current process (and one supported by Windows XP) is for instance
TLS, in which server and client exchange certificates; another is TTLS, in which
only the server supplies a certificate—the client is authenticated using only a
username and password.
After the authentication phase, a secure tunnel even without WEP encryption
has been set up, in which the access point is connected in the next step.
For this, the RADIUS server sends the so-called 'Master Secret', a session key
calculated during the negotiation, to the access point. The LAN behind it is
considered secure in this scenario, so that this transmission can be performed
in clear text.
With this session key, the access point now takes over the tunnel and can use
it to provide the actual WEP key to the client. Depending on the capabilities
of the access point hardware, this can be a true session key (that is, a WEP key
which will only be used for data packets between the access point and
precisely this client), or a so-called group key, which the access point will use
for communication with multiple clients. Classical WEP hardware can usually
handle only group keys, these being the four mentioned in the chapter on
WEP.
The particular advantage of this procedure is that the access point can
regularly change the WEP key over the EAP tunnel, that is, it can perform a
so-called rekeying. In this way, WEP keys can be replaced by new ones long
before they run the risk of being cracked due to IV collisions. A common 'use
time' for such WEP keys might be 5 minutes.
- Reference Manual 1
- LANCOM LCOS 3.50 1
- Contents 3
- 1Preface 10
- 2 System design 13
- System design 14
- Configuration and manage 15
- 3.2 Configuration software 16
- LANCAPI 21
- 3.5.1 How to start a trace 26
- 3.5.2 Overview of the keys 27
- 3.5.4 Combination commands 28
- 3.5.5 Examples 29
- 3.8 Command line interface 32
- 3.8.1 Command line reference 33
- 3.9 Scheduled Events 34
- 4 Management 37
- 4.1.1 Application examples 38
- Management 39
- 4.1.2 Configuration 42
- 5 Diagnosis 46
- Diagnosis 47
- 5.2.1 How to start a trace 48
- 5.2.2 Overview of the keys 49
- 5.2.4 Combination commands 50
- 5.2.5 Examples 51
- 6 Security 52
- Security 53
- 6.1.2 Login barring 54
- 6.2.1 Identification control 58
- 6.2.2 Callback 60
- 6.3 The security checklist 61
- 7 Routing and WAN connections 64
- 7.2 IP routing 66
- 7.2.2 Local routing 68
- Configuration tool Menu/table 72
- 7.2.4 SYN/ACK speedup 73
- 7.3.1 Simple masquerading 74
- Source IP Port 75
- 7.3.2 Inverse masquerading 78
- 7.4 N:N mapping 80
- 7.4.1 Application examples 81
- 7.4.2 Configuration 85
- 7.5.1 Name list 89
- 7.5.2 Layer list 90
- Parameter Meaning 91
- 7.6.1 The protocol 92
- In this column of 97
- 7.8 Callback functions 98
- Routing and WAN 100
- With this 100
- 8Firewall 104
- 8.1.3 The methods 105
- 8.1.4 The victims 106
- 8.2 What is a Firewall? 107
- Firewall 108
- 8.3 The LANCOM Firewall 114
- 8.3.2 Special protocols 119
- Configuration tool Run 132
- Firewall wizard 141
- Condition Description Object 148
- Limit Description Object 148
- Measure Description Object 150
- 8.3.9 Firewall diagnosis 151
- Configuration tool 152
- Element Element meaning 153
- Entry Description 155
- Flag Flag meaning 158
- 8.3.10 Firewall limitations 159
- Detection 160
- 9 Quality of Service 168
- Quality of Service 169
- 9.3 The queue concept 172
- Packet size in bytes 180
- 1 64 128 256 512 1024 1500 180
- 9.7 QoS configuration 183
- Transfer External 188
- 10 Virtual LANs (VLANs) 192
- 10.2.1 Frame tagging 193
- Virtual LANs (VLANs) 194
- 10.2.3 Application examples 195
- 10.3 Configuration of VLANs 198
- 10.3.2 The port table 199
- 11 Wireless LAN – WLAN 203
- Wireless LAN – WLAN 204
- 11.2.1 Some basic concepts 214
- 11.2.2 WEP 215
- 11.2.3 WEPplus 219
- 11.2.4 EAP and 802.1x 220
- 11.2.5 TKIP and WPA 223
- 11.2.6 AES and 802.11i 230
- 11.2.7 Summary 231
- 11.4.1 WLAN security 234
- Configuration tool Menu/Table 235
- 11.4.2 General WLAN settings 243
- √ (λ * d) 257
- 11.5.2 Antenna power 258
- Maximum distance [km] 262
- Mbps P2P P2mP 262
- Assumed cable loss: 9 dB 263
- Antenna gain: 8.5 dBi 263
- Assumed cable loss: 6 dB 263
- Office communications with 265
- 12.3 How to use the LANCAPI 270
- 12.4 The LANCOM CAPI Faxmodem 270
- 13.1.1 The DHCP server 272
- Server services for the LAN 273
- 13.2 DNS 277
- 13.2.2 DNS forwarding 279
- Configuration tool Run/Table 280
- 13.2.4 URL blocking 283
- 13.2.5 Dynamic DNS 284
- 13.3 Call charge management 285
- 13.4 The SYSLOG module 287
- Source Meaning Facility 289
- /etc/syslog.conf 290
- /var/log/lancom.log 290
- 14.1 What does VPN offer? 291
- Virtual Private Networks— 292
- 14.2 LANCOM VPN: an overview 295
- 14.2.3 LANCOM VPN functions 297
- 14.3.1 LAN-LAN coupling 298
- 14.5.3 Inspect VPN rules 309
- 14.6.1 Static/static 323
- 14.6.2 Dynamic/static 323
- Branch_office 324
- 14.7 How does VPN work? 326
- 14.7.2 Alternatives to IPSec 328
- 14.8.5 Key management – IKE 335
- 16 Index 338
Ryobi P300 manuals
Owner’s manuals and user’s guides for Tools Ryobi P300.
We providing 1 pdf manuals Ryobi P300 for download free by document types: User Manual
Komentáře k této Příručce